Stride: For monsters and Others

P.93 tells us that stride represents how fast a character moves. It and page 430 tell us the following strides:

Dwarves: 6
Men/Orcs/Trolls/Spiders: 7
Elves/Roden: 8
Wolves: 11
Horses: 13

How does one determine the stride for other creatures/monsters?

I thought, initally, that Stride = 2 x a creature’s speed multiplier from BWR and the Monster Burner. However, on closer inspection, that doesn’t apply to all creatures.

It holds true for bipeds:

Dwarves: Stride = 6 (speed multiplier under BWR = 3x)
Men/Orcs/Dwarves: Stride = 7 (speed multiplier under BWR = 3.5x)
Elves/Roden: Stride = 8 (speed multiplier under BWR 4x)

But for other creatures, that doesn’t hold true:

Great Spiders: Stride = 7 (speed multiplier under BWR = 4x)
Wolves: Stride = 11 (speed multiplier under BWR = 7x)
Horses: Stride = 13 (speed multiplier under BWR = 8x)

Is there some general formula that can be used to determine a creature’s BWG stride, based on its BWR speed multiplier? Or is this a case by case judgement call.